Peat moss is a multicellular, eukaryotic organism that belongs to the phylum Bryophyta of the Plantae kingdom. Peat moss is a a type of nonvascular land plant with true stomata and leafy, erect gametophytes.They lack a vascular system as well as a root system.
Many mosses have evolved a mutualistic relationship with fungi to absorb water and nutrients, making them capable of growing almost anywhere, including areas inhabited by humans such as buildings. Canadian sphagnum moss has been dried and burned as fuel for centuries, and, since the 1940s, has been sold for gardening purposes, holding air and water extremely well. (2). Sphagnum moss, which has a high acidity, prevents bacteria from growing and was used as an improvised bandage during WWI.(7)
(6)
The root system allows the peat moss to grow around the dog shaped mold.
(4).
Peat mosses have direct and substantial economic value, and have been used for centuries by humans. Majority of their usefulness arises from the fact that they have an extraordinary absorptive capacity.
Peatlands cover much of the area in the boreal zone of North America, Europe, and Asia and they constitute an important reservoir for global carbon and currently function as a carbon sink. In addition they have an important effects on gas fluxes that are determinants of global climate, nutrient cycling, regional patterns of hydrology, and biodiversity. (3).
Habitat and Niche:
Peat moss can be found growing in almost every terrestrial environment (all seven continents). Peat moss, like most species of nonvascular plants, grows in thick mats and occupies cool, moist habitats. Moss can thrive in soil, bare rock, on other plants such as trees, or even buildings. Peat moss is also found in wet woodlands, beside streams, in the moorlands, and, chiefly, bogs, where peat moss can be found in great quantities. These bogs are suitable for the survival of sphagnum moss, as they are very wet and are highly acidic; additionally, these bogs are generally unsuitable for the growth of any other plant species due to the acidic soil. Bogs are destroyed by humans in a similar way as rainforests are destroyed by humans (2).
Predator Avoidance:
To defend against predators such as slugs, mosses release a chemical called oxylipin, which is made by the oxidation of unsaturated fatty acids. Slugs and other predators will avoid the oxylipin, leaving the peat moss unharmed (8). The high acidity of the peat moss' environment makes it undesirable to consume by other species, and therefore it is rarely eaten (7).
Nutrient Acquisition:
Peat moss lack a root system or vascular system, meaning they cannot carry nutrients over vast distances to their tissues. Instead, peat moss is small enough to distribute water and nutrients throughout their bodies by diffusion. Water moves through the mats of moss, carrying vital nutrients, through capillary action. The leaflike structures of peat moss, known as gametophytes, perform photosynthesis to produce sugars for cell respiration.
Reproduction and Life Cycle:
Peat moss can reproduce both asexually, by breaking off bits of itself that will grow elsewhere,as well as sexually through spores (7).
The life cycle of peat moss is dependent on a source of external liquid water. Peat moss has both male and female reproductive structures, like most plants. It reproduces using spores. After the egg is fertilized in a structure called the archegonium, an embryo develops into a spore-bearing structure called the sporophyte, which will release spores into the environment to be dispersed.
Although all plants switch off between haploid gametophyte and diploid sporophyte, mosses gametophyte generation is dominant - these show as big and green. In reproduction the sperm must have water to swim through to reach the egg, explaining why they are dependent on an external source of liquid water (causing them to live in a moist environment). Usually morning dew is enough water for the sperm to travel.
Growth and Development:
After spores are released from the parent plant, they germinate in a moist area, suitable for growth. The spores then bud, which develop into leaflike structures called gametophytes that the peat moss can use for photosynthesis.
Integument:
Peat moss, like some other nonvascular land plants, have a thin cuticle to reduce water loss. Additionally, they have a special layer of protective tissue, called maternal tissue, to protect their embryos during reproduction.
Movement:
Peat moss spreads its spores into the air, where they are carried by wind, but do not move after its spores germinate. Then the moss begins to grow in the area in which it landed.(2) Due to the fact that spore movement is only limited by the wind,
Sensing the Environment:
If the environment of the sphagnum moss is too basic to be suitable, it will use facilitated diffusion to release hydrogen ions (H+) against the concentration gradient into the environment, lowering the pH of its habitat (9).
Gas Exchange:
Peat moss have true stomata in their leafy appendages, called gametophytes. Through these stoma, peat moss exchanges gases with its environment by absorbing carbon dioxide from the air for photosynthesis and releases oxygen.
Waste Removal:
Peat moss can directly diffuse waste materials out of its body into the environment. It releases oxygen, a byproduct of photosynthesis, into the air through its stomata, which can be found on the gametophytes. Sphagnum moss also releases unneeded hydrogen ions (H+) into its environment through diffusion, contributing to the high acidity of the bogs in which it thrives (7).
Environmental Physiology (temperature, water and salt regulation):
The structure of the gametophytes of peat moss is such that it can easily capture and hold any water that splashes onto it. Afterwards, the water can diffuse directly into the plant's tissue. Sphagnum moss leaves, being only one cell thick, have special dead cells, called hyaline cells, which act as designated water containers that store water (7).
Internal Circulation:
Water and nutrients circulate through the tissue and cells of peat moss through capillaries. The stems of sphagnum moss have many pores that help water travel up from the ground and supply the growing parts with water via capillary action (7).
Because mosses are primitive bryophytes, their small size allows for diffusion to move water in and out of the plant. In the stem there are small amounts of tissues allowing water flow, but there is no xylem or phloem to perform this function.
By simple capillary action, peat moss regulates levels of vital nutrients such as calcium and magnesium by exchanging these cations for hydrogen ions in the soil, which lowers the pH of its environment (7).
Chemical Control (i.e. endocrine system):
Bryophytes can transport hormones from cell to cell, by they also use exogenous, or outside sources of hormones to regulate and coordinate development. Thus, the environment in which a bryophyte is important to its growth so that it is exposed to hormones excreted by other plants.
Plant hormones are different from animal hormones. While an animal hormone produces a limited variety of effects, plant hormones act in combination with each other to produce a wide array of effects.
Review Questions:
1.Regarding reproduction, why must peat moss live in moist environments?
2. Why is peat moss used by so many gardeners?
Peat (sphagnum) moss (bryophyte)
Classification/Diagnostic Characteristics:
Peat moss is a multicellular, eukaryotic organism that belongs to the phylum Bryophyta of the Plantae kingdom. Peat moss is a a type of nonvascular land plant with true stomata and leafy, erect gametophytes.They lack a vascular system as well as a root system.Kingdom: Plantae
Phylum:Byrophyta
Class: Musci
Order: Sphagnales
Family: Sphagnaceae
Genus: Sphagnum
Species: Sphagnum quinquefarium
(5)
Relationship to Humans:
Many mosses have evolved a mutualistic relationship with fungi to absorb water and nutrients, making them capable of growing almost anywhere, including areas inhabited by humans such as buildings. Canadian sphagnum moss has been dried and burned as fuel for centuries, and, since the 1940s, has been sold for gardening purposes, holding air and water extremely well. (2). Sphagnum moss, which has a high acidity, prevents bacteria from growing and was used as an improvised bandage during WWI.(7)(6)
(4).
Peat mosses have direct and substantial economic value, and have been used for centuries by humans. Majority of their usefulness arises from the fact that they have an extraordinary absorptive capacity.
Peatlands cover much of the area in the boreal zone of North America, Europe, and Asia and they constitute an important reservoir for global carbon and currently function as a carbon sink. In addition they have an important effects on gas fluxes that are determinants of global climate, nutrient cycling, regional patterns of hydrology, and biodiversity. (3).
Habitat and Niche:
Peat moss can be found growing in almost every terrestrial environment (all seven continents). Peat moss, like most species of nonvascular plants, grows in thick mats and occupies cool, moist habitats. Moss can thrive in soil, bare rock, on other plants such as trees, or even buildings. Peat moss is also found in wet woodlands, beside streams, in the moorlands, and, chiefly, bogs, where peat moss can be found in great quantities. These bogs are suitable for the survival of sphagnum moss, as they are very wet and are highly acidic; additionally, these bogs are generally unsuitable for the growth of any other plant species due to the acidic soil. Bogs are destroyed by humans in a similar way as rainforests are destroyed by humans (2).Predator Avoidance:
To defend against predators such as slugs, mosses release a chemical called oxylipin, which is made by the oxidation of unsaturated fatty acids. Slugs and other predators will avoid the oxylipin, leaving the peat moss unharmed (8). The high acidity of the peat moss' environment makes it undesirable to consume by other species, and therefore it is rarely eaten (7).Nutrient Acquisition:
Peat moss lack a root system or vascular system, meaning they cannot carry nutrients over vast distances to their tissues. Instead, peat moss is small enough to distribute water and nutrients throughout their bodies by diffusion. Water moves through the mats of moss, carrying vital nutrients, through capillary action. The leaflike structures of peat moss, known as gametophytes, perform photosynthesis to produce sugars for cell respiration.Reproduction and Life Cycle:
Peat moss can reproduce both asexually, by breaking off bits of itself that will grow elsewhere,as well as sexually through spores (7).
The life cycle of peat moss is dependent on a source of external liquid water. Peat moss has both male and female reproductive structures, like most plants. It reproduces using spores. After the egg is fertilized in a structure called the archegonium, an embryo develops into a spore-bearing structure called the sporophyte, which will release spores into the environment to be dispersed.
Although all plants switch off between haploid gametophyte and diploid sporophyte, mosses gametophyte generation is dominant - these show as big and green. In reproduction the sperm must have water to swim through to reach the egg, explaining why they are dependent on an external source of liquid water (causing them to live in a moist environment). Usually morning dew is enough water for the sperm to travel.
Growth and Development:
After spores are released from the parent plant, they germinate in a moist area, suitable for growth. The spores then bud, which develop into leaflike structures called gametophytes that the peat moss can use for photosynthesis.Integument:
Peat moss, like some other nonvascular land plants, have a thin cuticle to reduce water loss. Additionally, they have a special layer of protective tissue, called maternal tissue, to protect their embryos during reproduction.Movement:
Peat moss spreads its spores into the air, where they are carried by wind, but do not move after its spores germinate. Then the moss begins to grow in the area in which it landed.(2) Due to the fact that spore movement is only limited by the wind,Sensing the Environment:
If the environment of the sphagnum moss is too basic to be suitable, it will use facilitated diffusion to release hydrogen ions (H+) against the concentration gradient into the environment, lowering the pH of its habitat (9).Gas Exchange:
Peat moss have true stomata in their leafy appendages, called gametophytes. Through these stoma, peat moss exchanges gases with its environment by absorbing carbon dioxide from the air for photosynthesis and releases oxygen.Waste Removal:
Peat moss can directly diffuse waste materials out of its body into the environment. It releases oxygen, a byproduct of photosynthesis, into the air through its stomata, which can be found on the gametophytes. Sphagnum moss also releases unneeded hydrogen ions (H+) into its environment through diffusion, contributing to the high acidity of the bogs in which it thrives (7).Environmental Physiology (temperature, water and salt regulation):
The structure of the gametophytes of peat moss is such that it can easily capture and hold any water that splashes onto it. Afterwards, the water can diffuse directly into the plant's tissue. Sphagnum moss leaves, being only one cell thick, have special dead cells, called hyaline cells, which act as designated water containers that store water (7).Internal Circulation:
Water and nutrients circulate through the tissue and cells of peat moss through capillaries. The stems of sphagnum moss have many pores that help water travel up from the ground and supply the growing parts with water via capillary action (7).Because mosses are primitive bryophytes, their small size allows for diffusion to move water in and out of the plant. In the stem there are small amounts of tissues allowing water flow, but there is no xylem or phloem to perform this function.
By simple capillary action, peat moss regulates levels of vital nutrients such as calcium and magnesium by exchanging these cations for hydrogen ions in the soil, which lowers the pH of its environment (7).
Chemical Control (i.e. endocrine system):
Bryophytes can transport hormones from cell to cell, by they also use exogenous, or outside sources of hormones to regulate and coordinate development. Thus, the environment in which a bryophyte is important to its growth so that it is exposed to hormones excreted by other plants.Plant hormones are different from animal hormones. While an animal hormone produces a limited variety of effects, plant hormones act in combination with each other to produce a wide array of effects.
Review Questions:
1.Regarding reproduction, why must peat moss live in moist environments?
2. Why is peat moss used by so many gardeners?
Sources
1. http://www.tulane.edu/~bfleury/diversity/labguide/mossfern.html
2. http://www.naturallifemagazine.com/0712/asknlpeat.html
3. http://www.amjbot.org/content/90/12/1777.full
4. http://www.menards.com/main/lawn-garden/lawn-plant-care/schultz-trade-sphagnum-peat-moss/p-1777764-c-10116.htm
5. http://homepage.univie.ac.at/eva.temsch/classif.html
6. http://lh4.ggpht.com/-kkCJ_O1Ok3U/Tymbxx9_p1I/AAAAAAAEGBQ/3LaT2Vr9aVM/IMG_0893.JPG?imgmax=800
7.http://www.moutere.com/stories/storyReader$54
8. http://phys.org/news195382125.html
9. http://webspace.qmul.ac.uk/clymo/Clymo-article-PDFs/14-Clymo-1973-Sphagnum-environment.pdf